An exhaust gas treatment device is mounted on a hydraulic excavator. As the exhaust gas treatment device, for example, a diesel particulate filter device (DPF), a diesel oxidation catalyst device (DOC), a selective catalytic reduction device (SCR), and the like are available. In particular, the selective catalytic reduction device reduces a nitrogen oxide in an exhaust gas to thereby purify the exhaust gas. A reducing agent used for this exhaust gas treatment is stored in a reducing agent tank.
Japanese Patent Laying-Open No. 2013-2082 (PTD 1) discloses a structure in which a bracket is provided in an equipment accommodating case which is located on the front side of a hydraulic oil tank and a fuel tank, a control valve is mounted on a support plate of the bracket, and a reducing agent tank is arranged between the support plate and a revolving frame.